610 lines
19 KiB
HTML
610 lines
19 KiB
HTML
<html>
|
|
<head>
|
|
<title>pcre2syntax specification</title>
|
|
</head>
|
|
<body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
|
|
<h1>pcre2syntax man page</h1>
|
|
<p>
|
|
Return to the <a href="index.html">PCRE2 index page</a>.
|
|
</p>
|
|
<p>
|
|
This page is part of the PCRE2 HTML documentation. It was generated
|
|
automatically from the original man page. If there is any nonsense in it,
|
|
please consult the man page, in case the conversion went wrong.
|
|
<br>
|
|
<ul>
|
|
<li><a name="TOC1" href="#SEC1">PCRE2 REGULAR EXPRESSION SYNTAX SUMMARY</a>
|
|
<li><a name="TOC2" href="#SEC2">QUOTING</a>
|
|
<li><a name="TOC3" href="#SEC3">ESCAPED CHARACTERS</a>
|
|
<li><a name="TOC4" href="#SEC4">CHARACTER TYPES</a>
|
|
<li><a name="TOC5" href="#SEC5">GENERAL CATEGORY PROPERTIES FOR \p and \P</a>
|
|
<li><a name="TOC6" href="#SEC6">PCRE2 SPECIAL CATEGORY PROPERTIES FOR \p and \P</a>
|
|
<li><a name="TOC7" href="#SEC7">SCRIPT NAMES FOR \p AND \P</a>
|
|
<li><a name="TOC8" href="#SEC8">CHARACTER CLASSES</a>
|
|
<li><a name="TOC9" href="#SEC9">QUANTIFIERS</a>
|
|
<li><a name="TOC10" href="#SEC10">ANCHORS AND SIMPLE ASSERTIONS</a>
|
|
<li><a name="TOC11" href="#SEC11">MATCH POINT RESET</a>
|
|
<li><a name="TOC12" href="#SEC12">ALTERNATION</a>
|
|
<li><a name="TOC13" href="#SEC13">CAPTURING</a>
|
|
<li><a name="TOC14" href="#SEC14">ATOMIC GROUPS</a>
|
|
<li><a name="TOC15" href="#SEC15">COMMENT</a>
|
|
<li><a name="TOC16" href="#SEC16">OPTION SETTING</a>
|
|
<li><a name="TOC17" href="#SEC17">NEWLINE CONVENTION</a>
|
|
<li><a name="TOC18" href="#SEC18">WHAT \R MATCHES</a>
|
|
<li><a name="TOC19" href="#SEC19">LOOKAHEAD AND LOOKBEHIND ASSERTIONS</a>
|
|
<li><a name="TOC20" href="#SEC20">BACKREFERENCES</a>
|
|
<li><a name="TOC21" href="#SEC21">SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)</a>
|
|
<li><a name="TOC22" href="#SEC22">CONDITIONAL PATTERNS</a>
|
|
<li><a name="TOC23" href="#SEC23">BACKTRACKING CONTROL</a>
|
|
<li><a name="TOC24" href="#SEC24">CALLOUTS</a>
|
|
<li><a name="TOC25" href="#SEC25">SEE ALSO</a>
|
|
<li><a name="TOC26" href="#SEC26">AUTHOR</a>
|
|
<li><a name="TOC27" href="#SEC27">REVISION</a>
|
|
</ul>
|
|
<br><a name="SEC1" href="#TOC1">PCRE2 REGULAR EXPRESSION SYNTAX SUMMARY</a><br>
|
|
<P>
|
|
The full syntax and semantics of the regular expressions that are supported by
|
|
PCRE2 are described in the
|
|
<a href="pcre2pattern.html"><b>pcre2pattern</b></a>
|
|
documentation. This document contains a quick-reference summary of the syntax.
|
|
</P>
|
|
<br><a name="SEC2" href="#TOC1">QUOTING</a><br>
|
|
<P>
|
|
<pre>
|
|
\x where x is non-alphanumeric is a literal x
|
|
\Q...\E treat enclosed characters as literal
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC3" href="#TOC1">ESCAPED CHARACTERS</a><br>
|
|
<P>
|
|
This table applies to ASCII and Unicode environments.
|
|
<pre>
|
|
\a alarm, that is, the BEL character (hex 07)
|
|
\cx "control-x", where x is any ASCII printing character
|
|
\e escape (hex 1B)
|
|
\f form feed (hex 0C)
|
|
\n newline (hex 0A)
|
|
\r carriage return (hex 0D)
|
|
\t tab (hex 09)
|
|
\0dd character with octal code 0dd
|
|
\ddd character with octal code ddd, or backreference
|
|
\o{ddd..} character with octal code ddd..
|
|
\U "U" if PCRE2_ALT_BSUX is set (otherwise is an error)
|
|
\uhhhh character with hex code hhhh (if PCRE2_ALT_BSUX is set)
|
|
\xhh character with hex code hh
|
|
\x{hhh..} character with hex code hhh..
|
|
</pre>
|
|
Note that \0dd is always an octal code. The treatment of backslash followed by
|
|
a non-zero digit is complicated; for details see the section
|
|
<a href="pcre2pattern.html#digitsafterbackslash">"Non-printing characters"</a>
|
|
in the
|
|
<a href="pcre2pattern.html"><b>pcre2pattern</b></a>
|
|
documentation, where details of escape processing in EBCDIC environments are
|
|
also given.
|
|
</P>
|
|
<P>
|
|
When \x is not followed by {, from zero to two hexadecimal digits are read,
|
|
but if PCRE2_ALT_BSUX is set, \x must be followed by two hexadecimal digits to
|
|
be recognized as a hexadecimal escape; otherwise it matches a literal "x".
|
|
Likewise, if \u (in ALT_BSUX mode) is not followed by four hexadecimal digits,
|
|
it matches a literal "u".
|
|
</P>
|
|
<br><a name="SEC4" href="#TOC1">CHARACTER TYPES</a><br>
|
|
<P>
|
|
<pre>
|
|
. any character except newline;
|
|
in dotall mode, any character whatsoever
|
|
\C one code unit, even in UTF mode (best avoided)
|
|
\d a decimal digit
|
|
\D a character that is not a decimal digit
|
|
\h a horizontal white space character
|
|
\H a character that is not a horizontal white space character
|
|
\N a character that is not a newline
|
|
\p{<i>xx</i>} a character with the <i>xx</i> property
|
|
\P{<i>xx</i>} a character without the <i>xx</i> property
|
|
\R a newline sequence
|
|
\s a white space character
|
|
\S a character that is not a white space character
|
|
\v a vertical white space character
|
|
\V a character that is not a vertical white space character
|
|
\w a "word" character
|
|
\W a "non-word" character
|
|
\X a Unicode extended grapheme cluster
|
|
</pre>
|
|
\C is dangerous because it may leave the current matching point in the middle
|
|
of a UTF-8 or UTF-16 character. The application can lock out the use of \C by
|
|
setting the PCRE2_NEVER_BACKSLASH_C option. It is also possible to build PCRE2
|
|
with the use of \C permanently disabled.
|
|
</P>
|
|
<P>
|
|
By default, \d, \s, and \w match only ASCII characters, even in UTF-8 mode
|
|
or in the 16-bit and 32-bit libraries. However, if locale-specific matching is
|
|
happening, \s and \w may also match characters with code points in the range
|
|
128-255. If the PCRE2_UCP option is set, the behaviour of these escape
|
|
sequences is changed to use Unicode properties and they match many more
|
|
characters.
|
|
</P>
|
|
<br><a name="SEC5" href="#TOC1">GENERAL CATEGORY PROPERTIES FOR \p and \P</a><br>
|
|
<P>
|
|
<pre>
|
|
C Other
|
|
Cc Control
|
|
Cf Format
|
|
Cn Unassigned
|
|
Co Private use
|
|
Cs Surrogate
|
|
|
|
L Letter
|
|
Ll Lower case letter
|
|
Lm Modifier letter
|
|
Lo Other letter
|
|
Lt Title case letter
|
|
Lu Upper case letter
|
|
L& Ll, Lu, or Lt
|
|
|
|
M Mark
|
|
Mc Spacing mark
|
|
Me Enclosing mark
|
|
Mn Non-spacing mark
|
|
|
|
N Number
|
|
Nd Decimal number
|
|
Nl Letter number
|
|
No Other number
|
|
|
|
P Punctuation
|
|
Pc Connector punctuation
|
|
Pd Dash punctuation
|
|
Pe Close punctuation
|
|
Pf Final punctuation
|
|
Pi Initial punctuation
|
|
Po Other punctuation
|
|
Ps Open punctuation
|
|
|
|
S Symbol
|
|
Sc Currency symbol
|
|
Sk Modifier symbol
|
|
Sm Mathematical symbol
|
|
So Other symbol
|
|
|
|
Z Separator
|
|
Zl Line separator
|
|
Zp Paragraph separator
|
|
Zs Space separator
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC6" href="#TOC1">PCRE2 SPECIAL CATEGORY PROPERTIES FOR \p and \P</a><br>
|
|
<P>
|
|
<pre>
|
|
Xan Alphanumeric: union of properties L and N
|
|
Xps POSIX space: property Z or tab, NL, VT, FF, CR
|
|
Xsp Perl space: property Z or tab, NL, VT, FF, CR
|
|
Xuc Univerally-named character: one that can be
|
|
represented by a Universal Character Name
|
|
Xwd Perl word: property Xan or underscore
|
|
</pre>
|
|
Perl and POSIX space are now the same. Perl added VT to its space character set
|
|
at release 5.18.
|
|
</P>
|
|
<br><a name="SEC7" href="#TOC1">SCRIPT NAMES FOR \p AND \P</a><br>
|
|
<P>
|
|
Ahom,
|
|
Anatolian_Hieroglyphs,
|
|
Arabic,
|
|
Armenian,
|
|
Avestan,
|
|
Balinese,
|
|
Bamum,
|
|
Bassa_Vah,
|
|
Batak,
|
|
Bengali,
|
|
Bopomofo,
|
|
Brahmi,
|
|
Braille,
|
|
Buginese,
|
|
Buhid,
|
|
Canadian_Aboriginal,
|
|
Carian,
|
|
Caucasian_Albanian,
|
|
Chakma,
|
|
Cham,
|
|
Cherokee,
|
|
Common,
|
|
Coptic,
|
|
Cuneiform,
|
|
Cypriot,
|
|
Cyrillic,
|
|
Deseret,
|
|
Devanagari,
|
|
Duployan,
|
|
Egyptian_Hieroglyphs,
|
|
Elbasan,
|
|
Ethiopic,
|
|
Georgian,
|
|
Glagolitic,
|
|
Gothic,
|
|
Grantha,
|
|
Greek,
|
|
Gujarati,
|
|
Gurmukhi,
|
|
Han,
|
|
Hangul,
|
|
Hanunoo,
|
|
Hatran,
|
|
Hebrew,
|
|
Hiragana,
|
|
Imperial_Aramaic,
|
|
Inherited,
|
|
Inscriptional_Pahlavi,
|
|
Inscriptional_Parthian,
|
|
Javanese,
|
|
Kaithi,
|
|
Kannada,
|
|
Katakana,
|
|
Kayah_Li,
|
|
Kharoshthi,
|
|
Khmer,
|
|
Khojki,
|
|
Khudawadi,
|
|
Lao,
|
|
Latin,
|
|
Lepcha,
|
|
Limbu,
|
|
Linear_A,
|
|
Linear_B,
|
|
Lisu,
|
|
Lycian,
|
|
Lydian,
|
|
Mahajani,
|
|
Malayalam,
|
|
Mandaic,
|
|
Manichaean,
|
|
Meetei_Mayek,
|
|
Mende_Kikakui,
|
|
Meroitic_Cursive,
|
|
Meroitic_Hieroglyphs,
|
|
Miao,
|
|
Modi,
|
|
Mongolian,
|
|
Mro,
|
|
Multani,
|
|
Myanmar,
|
|
Nabataean,
|
|
New_Tai_Lue,
|
|
Nko,
|
|
Ogham,
|
|
Ol_Chiki,
|
|
Old_Hungarian,
|
|
Old_Italic,
|
|
Old_North_Arabian,
|
|
Old_Permic,
|
|
Old_Persian,
|
|
Old_South_Arabian,
|
|
Old_Turkic,
|
|
Oriya,
|
|
Osmanya,
|
|
Pahawh_Hmong,
|
|
Palmyrene,
|
|
Pau_Cin_Hau,
|
|
Phags_Pa,
|
|
Phoenician,
|
|
Psalter_Pahlavi,
|
|
Rejang,
|
|
Runic,
|
|
Samaritan,
|
|
Saurashtra,
|
|
Sharada,
|
|
Shavian,
|
|
Siddham,
|
|
SignWriting,
|
|
Sinhala,
|
|
Sora_Sompeng,
|
|
Sundanese,
|
|
Syloti_Nagri,
|
|
Syriac,
|
|
Tagalog,
|
|
Tagbanwa,
|
|
Tai_Le,
|
|
Tai_Tham,
|
|
Tai_Viet,
|
|
Takri,
|
|
Tamil,
|
|
Telugu,
|
|
Thaana,
|
|
Thai,
|
|
Tibetan,
|
|
Tifinagh,
|
|
Tirhuta,
|
|
Ugaritic,
|
|
Vai,
|
|
Warang_Citi,
|
|
Yi.
|
|
</P>
|
|
<br><a name="SEC8" href="#TOC1">CHARACTER CLASSES</a><br>
|
|
<P>
|
|
<pre>
|
|
[...] positive character class
|
|
[^...] negative character class
|
|
[x-y] range (can be used for hex characters)
|
|
[[:xxx:]] positive POSIX named set
|
|
[[:^xxx:]] negative POSIX named set
|
|
|
|
alnum alphanumeric
|
|
alpha alphabetic
|
|
ascii 0-127
|
|
blank space or tab
|
|
cntrl control character
|
|
digit decimal digit
|
|
graph printing, excluding space
|
|
lower lower case letter
|
|
print printing, including space
|
|
punct printing, excluding alphanumeric
|
|
space white space
|
|
upper upper case letter
|
|
word same as \w
|
|
xdigit hexadecimal digit
|
|
</pre>
|
|
In PCRE2, POSIX character set names recognize only ASCII characters by default,
|
|
but some of them use Unicode properties if PCRE2_UCP is set. You can use
|
|
\Q...\E inside a character class.
|
|
</P>
|
|
<br><a name="SEC9" href="#TOC1">QUANTIFIERS</a><br>
|
|
<P>
|
|
<pre>
|
|
? 0 or 1, greedy
|
|
?+ 0 or 1, possessive
|
|
?? 0 or 1, lazy
|
|
* 0 or more, greedy
|
|
*+ 0 or more, possessive
|
|
*? 0 or more, lazy
|
|
+ 1 or more, greedy
|
|
++ 1 or more, possessive
|
|
+? 1 or more, lazy
|
|
{n} exactly n
|
|
{n,m} at least n, no more than m, greedy
|
|
{n,m}+ at least n, no more than m, possessive
|
|
{n,m}? at least n, no more than m, lazy
|
|
{n,} n or more, greedy
|
|
{n,}+ n or more, possessive
|
|
{n,}? n or more, lazy
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC10" href="#TOC1">ANCHORS AND SIMPLE ASSERTIONS</a><br>
|
|
<P>
|
|
<pre>
|
|
\b word boundary
|
|
\B not a word boundary
|
|
^ start of subject
|
|
also after an internal newline in multiline mode
|
|
(after any newline if PCRE2_ALT_CIRCUMFLEX is set)
|
|
\A start of subject
|
|
$ end of subject
|
|
also before newline at end of subject
|
|
also before internal newline in multiline mode
|
|
\Z end of subject
|
|
also before newline at end of subject
|
|
\z end of subject
|
|
\G first matching position in subject
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC11" href="#TOC1">MATCH POINT RESET</a><br>
|
|
<P>
|
|
<pre>
|
|
\K reset start of match
|
|
</pre>
|
|
\K is honoured in positive assertions, but ignored in negative ones.
|
|
</P>
|
|
<br><a name="SEC12" href="#TOC1">ALTERNATION</a><br>
|
|
<P>
|
|
<pre>
|
|
expr|expr|expr...
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC13" href="#TOC1">CAPTURING</a><br>
|
|
<P>
|
|
<pre>
|
|
(...) capturing group
|
|
(?<name>...) named capturing group (Perl)
|
|
(?'name'...) named capturing group (Perl)
|
|
(?P<name>...) named capturing group (Python)
|
|
(?:...) non-capturing group
|
|
(?|...) non-capturing group; reset group numbers for
|
|
capturing groups in each alternative
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC14" href="#TOC1">ATOMIC GROUPS</a><br>
|
|
<P>
|
|
<pre>
|
|
(?>...) atomic, non-capturing group
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC15" href="#TOC1">COMMENT</a><br>
|
|
<P>
|
|
<pre>
|
|
(?#....) comment (not nestable)
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC16" href="#TOC1">OPTION SETTING</a><br>
|
|
<P>
|
|
<pre>
|
|
(?i) caseless
|
|
(?J) allow duplicate names
|
|
(?m) multiline
|
|
(?n) no auto capture
|
|
(?s) single line (dotall)
|
|
(?U) default ungreedy (lazy)
|
|
(?x) extended: ignore white space except in classes
|
|
(?xx) as (?x) but also ignore space and tab in classes
|
|
(?-...) unset option(s)
|
|
</pre>
|
|
The following are recognized only at the very start of a pattern or after one
|
|
of the newline or \R options with similar syntax. More than one of them may
|
|
appear. For the first three, d is a decimal number.
|
|
<pre>
|
|
(*LIMIT_DEPTH=d) set the backtracking limit to d
|
|
(*LIMIT_HEAP=d) set the heap size limit to d kilobytes
|
|
(*LIMIT_MATCH=d) set the match limit to d
|
|
(*NOTEMPTY) set PCRE2_NOTEMPTY when matching
|
|
(*NOTEMPTY_ATSTART) set PCRE2_NOTEMPTY_ATSTART when matching
|
|
(*NO_AUTO_POSSESS) no auto-possessification (PCRE2_NO_AUTO_POSSESS)
|
|
(*NO_DOTSTAR_ANCHOR) no .* anchoring (PCRE2_NO_DOTSTAR_ANCHOR)
|
|
(*NO_JIT) disable JIT optimization
|
|
(*NO_START_OPT) no start-match optimization (PCRE2_NO_START_OPTIMIZE)
|
|
(*UTF) set appropriate UTF mode for the library in use
|
|
(*UCP) set PCRE2_UCP (use Unicode properties for \d etc)
|
|
</pre>
|
|
Note that LIMIT_DEPTH, LIMIT_HEAP, and LIMIT_MATCH can only reduce the value of
|
|
the limits set by the caller of <b>pcre2_match()</b> or <b>pcre2_dfa_match()</b>,
|
|
not increase them. LIMIT_RECURSION is an obsolete synonym for LIMIT_DEPTH. The
|
|
application can lock out the use of (*UTF) and (*UCP) by setting the
|
|
PCRE2_NEVER_UTF or PCRE2_NEVER_UCP options, respectively, at compile time.
|
|
</P>
|
|
<br><a name="SEC17" href="#TOC1">NEWLINE CONVENTION</a><br>
|
|
<P>
|
|
These are recognized only at the very start of the pattern or after option
|
|
settings with a similar syntax.
|
|
<pre>
|
|
(*CR) carriage return only
|
|
(*LF) linefeed only
|
|
(*CRLF) carriage return followed by linefeed
|
|
(*ANYCRLF) all three of the above
|
|
(*ANY) any Unicode newline sequence
|
|
(*NUL) the NUL character (binary zero)
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC18" href="#TOC1">WHAT \R MATCHES</a><br>
|
|
<P>
|
|
These are recognized only at the very start of the pattern or after option
|
|
setting with a similar syntax.
|
|
<pre>
|
|
(*BSR_ANYCRLF) CR, LF, or CRLF
|
|
(*BSR_UNICODE) any Unicode newline sequence
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC19" href="#TOC1">LOOKAHEAD AND LOOKBEHIND ASSERTIONS</a><br>
|
|
<P>
|
|
<pre>
|
|
(?=...) positive look ahead
|
|
(?!...) negative look ahead
|
|
(?<=...) positive look behind
|
|
(?<!...) negative look behind
|
|
</pre>
|
|
Each top-level branch of a look behind must be of a fixed length.
|
|
</P>
|
|
<br><a name="SEC20" href="#TOC1">BACKREFERENCES</a><br>
|
|
<P>
|
|
<pre>
|
|
\n reference by number (can be ambiguous)
|
|
\gn reference by number
|
|
\g{n} reference by number
|
|
\g+n relative reference by number (PCRE2 extension)
|
|
\g-n relative reference by number
|
|
\g{+n} relative reference by number (PCRE2 extension)
|
|
\g{-n} relative reference by number
|
|
\k<name> reference by name (Perl)
|
|
\k'name' reference by name (Perl)
|
|
\g{name} reference by name (Perl)
|
|
\k{name} reference by name (.NET)
|
|
(?P=name) reference by name (Python)
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC21" href="#TOC1">SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)</a><br>
|
|
<P>
|
|
<pre>
|
|
(?R) recurse whole pattern
|
|
(?n) call subpattern by absolute number
|
|
(?+n) call subpattern by relative number
|
|
(?-n) call subpattern by relative number
|
|
(?&name) call subpattern by name (Perl)
|
|
(?P>name) call subpattern by name (Python)
|
|
\g<name> call subpattern by name (Oniguruma)
|
|
\g'name' call subpattern by name (Oniguruma)
|
|
\g<n> call subpattern by absolute number (Oniguruma)
|
|
\g'n' call subpattern by absolute number (Oniguruma)
|
|
\g<+n> call subpattern by relative number (PCRE2 extension)
|
|
\g'+n' call subpattern by relative number (PCRE2 extension)
|
|
\g<-n> call subpattern by relative number (PCRE2 extension)
|
|
\g'-n' call subpattern by relative number (PCRE2 extension)
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC22" href="#TOC1">CONDITIONAL PATTERNS</a><br>
|
|
<P>
|
|
<pre>
|
|
(?(condition)yes-pattern)
|
|
(?(condition)yes-pattern|no-pattern)
|
|
|
|
(?(n) absolute reference condition
|
|
(?(+n) relative reference condition
|
|
(?(-n) relative reference condition
|
|
(?(<name>) named reference condition (Perl)
|
|
(?('name') named reference condition (Perl)
|
|
(?(name) named reference condition (PCRE2, deprecated)
|
|
(?(R) overall recursion condition
|
|
(?(Rn) specific numbered group recursion condition
|
|
(?(R&name) specific named group recursion condition
|
|
(?(DEFINE) define subpattern for reference
|
|
(?(VERSION[>]=n.m) test PCRE2 version
|
|
(?(assert) assertion condition
|
|
</pre>
|
|
Note the ambiguity of (?(R) and (?(Rn) which might be named reference
|
|
conditions or recursion tests. Such a condition is interpreted as a reference
|
|
condition if the relevant named group exists.
|
|
</P>
|
|
<br><a name="SEC23" href="#TOC1">BACKTRACKING CONTROL</a><br>
|
|
<P>
|
|
The following act immediately they are reached:
|
|
<pre>
|
|
(*ACCEPT) force successful match
|
|
(*FAIL) force backtrack; synonym (*F)
|
|
(*MARK:NAME) set name to be passed back; synonym (*:NAME)
|
|
</pre>
|
|
The following act only when a subsequent match failure causes a backtrack to
|
|
reach them. They all force a match failure, but they differ in what happens
|
|
afterwards. Those that advance the start-of-match point do so only if the
|
|
pattern is not anchored.
|
|
<pre>
|
|
(*COMMIT) overall failure, no advance of starting point
|
|
(*PRUNE) advance to next starting character
|
|
(*PRUNE:NAME) equivalent to (*MARK:NAME)(*PRUNE)
|
|
(*SKIP) advance to current matching position
|
|
(*SKIP:NAME) advance to position corresponding to an earlier
|
|
(*MARK:NAME); if not found, the (*SKIP) is ignored
|
|
(*THEN) local failure, backtrack to next alternation
|
|
(*THEN:NAME) equivalent to (*MARK:NAME)(*THEN)
|
|
</PRE>
|
|
</P>
|
|
<br><a name="SEC24" href="#TOC1">CALLOUTS</a><br>
|
|
<P>
|
|
<pre>
|
|
(?C) callout (assumed number 0)
|
|
(?Cn) callout with numerical data n
|
|
(?C"text") callout with string data
|
|
</pre>
|
|
The allowed string delimiters are ` ' " ^ % # $ (which are the same for the
|
|
start and the end), and the starting delimiter { matched with the ending
|
|
delimiter }. To encode the ending delimiter within the string, double it.
|
|
</P>
|
|
<br><a name="SEC25" href="#TOC1">SEE ALSO</a><br>
|
|
<P>
|
|
<b>pcre2pattern</b>(3), <b>pcre2api</b>(3), <b>pcre2callout</b>(3),
|
|
<b>pcre2matching</b>(3), <b>pcre2</b>(3).
|
|
</P>
|
|
<br><a name="SEC26" href="#TOC1">AUTHOR</a><br>
|
|
<P>
|
|
Philip Hazel
|
|
<br>
|
|
University Computing Service
|
|
<br>
|
|
Cambridge, England.
|
|
<br>
|
|
</P>
|
|
<br><a name="SEC27" href="#TOC1">REVISION</a><br>
|
|
<P>
|
|
Last updated: 17 June 2017
|
|
<br>
|
|
Copyright © 1997-2017 University of Cambridge.
|
|
<br>
|
|
<p>
|
|
Return to the <a href="index.html">PCRE2 index page</a>.
|
|
</p>
|